A method of spiking a mixed acid liquid in a reactor is performed under three modes of control, a based-on-charge mode control, a based-on-time mode control, and a based-on-time-and-charge mode control. In the based-on-charge mode control, spike timing and spiking amount of an acid liquid are set for each lot of product. In the based-on-time mode control, the spike timing and the spiking amount of the acid liquid are set for each timing point. In the based-on-time-and-charge mode control, the spike timing and the spiking amount of an acid liquid are set for each lot of product and each timing point. Thereby, a concentration of the mixed acid liquid is controlled at a targetlevel.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of spiking a mixed acid liquid in a reactor by using a computer to control a concentration of the mixed acid liquid, the concentration of the mixed acid liquid being controlled at a target level under a based-on-charge mode, a based-on-time mode, or a based-on-time-and-charge mode, the based-on-charge mode control comprising: providing a charge list including a plurality of lot numbers of product and a plurality of spiking amounts of a first acid liquid corresponding lot numbers of product; and introducing the spiking amounts of the first acid into the reactor in an order corresponding to the lot numbers of product; the based-on-time mode control comprising: providing a timing list including a plurality of timing points and a plurality of spiking amounts of a second acid liquid corresponding to the timing points; and introducing the spiking amounts of the second acid liquid into the reactor at the corresponding timing points; and the based-on-time-and-charge mode control comprising: providing a charge/timing list including spiking amounts and spike timing points; and introducing the spiking amounts of the first acid into the reactor based on the lot numbers of product and the spike timing points.
2. The method of claim 1 , wherein when a wafer is being etched in the reactor, the acid liquid is not introduced into the reactor.
3. A method of spiking a mixed acid liquid in a reactor by using a computer to control a concentration of the mixed acid liquid, the concentration of the mixed acid liquid being controlled at a target level under a based-on-time-and-charge mode, wherein the based-on-time and-charge mode control comprises: providing a charge/timing list including spiking amounts and spike timing points; and introducing the spiking amounts of the first acid into the reactor based on lot numbers of product and the spike timing points.
4. The method of claim 3 , wherein when a wafer is being etched in the reactor, the acid liquid is not introduced into the reactor.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 30, 2002
February 8, 2005
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